Cynips gemmula
agamic forms [partial; excluding Acraspis prinoides. Tentatively assigned to Acraspis echini based on host.]
GALLS OF AGAMIC FORMS. — Moderately large, spherical, roughly faceted, with short spines. Usually monothalamous, often with two or three cells in variety cruenta; the normal galls strictly spherical, up to 17.0 mm. in diameter; the surfaces closely set with numerous, bluntly cone-shaped projections which usually terminate in short, stiff, and blunt spines; the cones plus the spines usually not over 1.5 mm. in length; the young galls light greenish or yellow tinged with red, the older galls light buff yellow to brown and blackish. Internally compact crystalline, the walls very thick, the entire gall consequently solid ex- cept for the centrally placed larval cell which is up to 2.2 mm. in diameter and without a distinct cell wall. Attached to either the upper or under surfaces, usually to the mid-rib but sometimes on lateral veins, on leaves of chestnut oaks (known from Q. prinoides, Q. Michauxii, Q. Muhlenbergii ) .
[Kinsey goes on to describe several varieties on Quercus michauxii, with varying spine length. See paper for details.]
Cynips pezomachoides variety echinoides, new name
agamic form
Acraspis echini
Philonix echini
Gall.--Known only from the spiny form; on leaves of Quercus bicolor.
Range: FL
This insect is recognizable by its nearly uniformly bright rufous color, its more shortened parapsidal grooves, and its usually larger size. It is known only from the type material, and this is insufficient data to show whether the variety ranges on the swamp white oak, Q. bicolor, thruout the Atlantic Coastal Plain area, or along the Gulf into eastern Texas, or is confined to Florida.
Ashmead described the galls as precisely similar to those of “erinacei,” meaning a spiny form of this species. The gall described and figured by Beutenmuller, perhaps from the type material in the Philadelphia Academy, is intermediate between the naked and spiny forms. There are no galls among the types in the National Museum.
Ashmead bred adults in November. He expressed surprise that he had found this species on Q. bicolor without finding it on Q. Prinus, for, he says, Q. bicolor “is considered by many botanists only a variety of Quercus prinus; galls found on one are very apt to be found on both, and insects are good botanists.” As a matter of fact, these insects are better judges of the relationships of the oaks than anyone who would consider Q. bicolor a variety of Q. Prinus. Long ago in the history of our insects there was a division on this very question, and Cynips gemmula and its varieties claimed the exclusive rights to Quercus Prinus, prinoides, Michauxii, and Muhlenbergii, while Cynips pezomachoides accepted Q. alba and bicolor. Modern botanists acknowledge this to be the correct grouping of these oaks (cf. Trelease, 1924, Nat. Acad. Sci. Mem. 20:102-111). Echinoides, as a variety of pezomachoides, is not departing from the ancestral traditions when it takes up its dwelling on Q. bicolor.
